Analysis of relapse after transplantation in acute leukemia: A comparative on second allogeneic hematopoietic cell transplantation and donor lymphocyte infusions

Efficacy and safety of blinatumomab for the treatment of patients relapsing after allogeneic hematopoietic cell transplantation: a systemic review and meta-analysis

OBJECTIVE

We aim to evaluate the efficacy and safety of blinatumomab for the treatment of post-transplant relapse patients with acute lymphoblastic leukemia (ALL).

METHODS

The search was conducted using several databases including the PubMed, Cochrane Library, Embase, Chinese National Knowledge Infrastructure (CNKI) and Wanfang Data Knowledge Service Platform to collect clinical studies related to blinatumomab. The primary outcome measures were complete remission (CR), 1-year overall survival (OS), 2-year OS, median OS and adverse events (AEs). Grade ≥3 AEs were mainly analyzed for safety, including anemia, thrombocytopenia, neutropenia, encephalopathy, peripheral paresthesia, tremor and cytokine release syndrome (CRS).

RESULTS

A total of 7 studies, involving a total of 292 patients were included in the analysis. The analysis results showed CR rate of 48%, 1-year OS rate of 40% 2-year OS rate of 21%, median OS 7.47. For safety analysis, the incidence of grade ≥3 AEs, including the incidence of grade ≥3 anemic toxicity was 13% , the incidence of grade ≥3 thrombocytopenia toxicity was 7% , the incidence of grade ≥3 neutropenia toxicity 24%, the incidence of grade ≥3 encephalopathic toxicity was 4% , the incidence of grade ≥3 peripheral paresthesia toxicity 4%, the incidence of grade ≥3 tremor toxicity 8% , the incidence of grade ≥3 CRS toxicity was 4%.

CONCLUSION

Blinatumomab may be a safe and an effective treatment approach for post-transplant relapse patients with ALL, but its long-term efficacy is still a big challenge. In regard to Regarding AEs, serious CRS and neurological events were infrequent and manageable.

A case of posttransplant isolated extramedullary relapse of acute lymphoblastic leukemia achieving durable treatment-free remission with blinatumomab and donor lymphocyte infusion

Acute lymphoblastic leukemia (ALL) relapsed after allogeneic hematopoietic cell transplantation (allo-HCT) has a catastrophic prognosis. Blinatumomab, a CD3/CD19-directed bispecific T cell engager, is reportedly effective for advanced B-cell ALL (B-ALL), even after allo-HCT. However, the efficacy of blinatumomab in extramedullary relapse (EMR) is controversial. Donor lymphocyte infusion (DLI) is another immunological treatment worth considering for ALL relapsed after allo-HCT. We report the case of a 56-year-old woman with B-ALL. Allo-HCT was performed during the second complete remission (CR). Thirteen months after allo-HCT, isolated EMR (iEMR) of B-ALL developed without bone marrow lesions. A third CR was achieved with 2 cycles of blinatumomab. An additional four cycles each of blinatumomab and DLI were then administered. The patient did not develop graft-versus-host disease and has confirmed 2-year treatment-free remission without a second allo-HCT. Therefore, blinatumomab was considered an effective salvage therapy for iEMR of B-ALL after allo-HCT, because iEMR could have a lower tumor burden than that seen in systemic relapse, and low tumor burden was a prognostic factor for response to blinatumomab. Furthermore, immunological consolidation therapies could only provoke graft-versus-leukemia effects if the imbalanced effector/target ratio was restored and the tumor burden was lowered through immunosurveillance.

Phase II trial of hypomethylating agent combined with nivolumab for acute myeloid leukaemia relapse after allogeneic haematopoietic cell transplantation-Immune signature correlates with response

Acute myeloid leukaemia (AML) relapse after allogeneic haematopoietic cell transplantation (allo-HCT) is often driven by immune-related mechanisms and associated with poor prognosis. Immune checkpoint inhibitors combined with hypomethylating agents (HMA) may restore or enhance the graft-versus-leukaemia effect. Still, data about using this combination regimen after allo-HCT are limited. We conducted a prospective, phase II, open-label, single-arm study in which we treated patients with haematological AML relapse after allo-HCT with HMA plus the anti-PD-1 antibody nivolumab. The response was correlated with DNA-, RNA- and protein-based single-cell technology assessments to identify biomarkers associated with therapeutic efficacy. Sixteen patients received a median number of 2 (range 1-7) nivolumab applications. The overall response rate (CR/PR) at day 42 was 25%, and another 25% of the patients achieved stable disease. The median overall survival was 15.6 months. High-parametric cytometry documented a higher frequency of activated (ICOS+ , HLA-DR+ ), low senescence (KLRG1- , CD57- ) CD8+ effector T cells in responders. We confirmed these findings in a preclinical model. Single-cell transcriptomics revealed a pro-inflammatory rewiring of the expression profile of T and myeloid cells in responders. In summary, the study indicates that the post-allo-HCT HMA/nivolumab combination induces anti-AML immune responses in selected patients and could be considered as a bridging approach to a second allo-HCT. Trial-registration: EudraCT-No. 2017-002194-18.

Long-term outcome of second allogeneic hematopoietic stem cell transplantation (HSCT2) for primary graft failure in patients with acute leukemia in remission: A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Second transplantation (HSCT2) is a potential treatment for primary graft failure (pGF). We assessed the outcome of HSCT2, performed between 2000 and 2021, for pGF in 243 patients with acute leukemia. Median age was 44.8 years. Conditioning at first HSCT (HSCT1) was myeloablative (MAC) in 58.4%. Median time from HSCT1 to HSCT2 was 48 days. Donors for HSCT2 were the same as for HSCT1 in 49%. Engraftment post HSCT2 was achieved by 73.7% of patients. The incidence of acute (a) graft versus host disease (GVHD) grades II-IV and III-IV was 23.2 and 8.1%. 5-year total and extensive chronic (c) GVHD was 22.3 and 10.1%. 5-year nonrelapse mortality (NRM), relapse incidence (RI), leukemia-free survival (LFS), overall survival (OS) and GVHD free, relapse-free survival (GRFS) was 51.6, 18.8, 29.6, 30.7 and 22.4%, respectively. Infections were the main cause of death. In multivariable analysis, being transplanted at second vs. first remission, lower Karnofsky performance status (KPS; <90) and receiving MAC at HSCT1 were adverse prognostic factors for NRM, LFS, OS, and GRFS, as was increased age for NRM, LFS, OS. We conclude that HSCT2 can rescue about a third of the patients who experienced pGF, but NRM is as high as 50%.

Late relapse after hematopoietic stem cell transplantation for acute leukemia: a retrospective study by SFGM-TC

Late relapse (LR) after allogeneic hematopoietic stem cell transplantation (AHSCT) for acute leukemia is a rare event (nearly 4.5%) and raises the questions of prognosis and outcome after salvage therapy. We performed a retrospective multicentric study between January 1, 2010, and December 31, 2016, using data from the French national retrospective register ProMISe provided by the SFGM-TC (French Society for Bone Marrow Transplantation and Cellular Therapy). We included patients presenting with LR, defined as a relapse occurring at least 2 years after AHSCT. We used the Cox model to identify prognosis factors associated with LR. During the study period, a total of 7582 AHSCTs were performed in 29 centers, and 33.8% of patients relapsed. Among them, 319 (12.4%) were considered to have LR, representing an incidence of 4.2% for the entire cohort. The full dataset was available for 290 patients, including 250 (86.2%) with acute myeloid leukemia and 40 (13.8%) with acute lymphoid leukemia. The median interval from AHSCT to LR was 38.2 months (interquartile range [IQR], 29.2 to 49.7 months), and 27.2% of the patients had extramedullary involvement at LR (17.2% exclusively and 10% associated with medullary involvement). One-third of the patients had persistent full donor chimerism at LR. Median overall survival (OS) after LR was 19.9 months (IQR, 5.6 to 46.4 months). The most common salvage therapy was induction regimen (55.5%), with complete remission (CR) obtained in 50.7% of cases. Ninety-four patients (38.5%) underwent a second AHSCT, with a median OS of 20.4 months (IQR, 7.1 to 49.1 months). Nonrelapse mortality after second AHSCT was 18.2%. The Cox model identified the following factors as associated with delay of LR: disease status not in first CR at first HSCT (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.04 to 1.64; P = .02) and the use of post-transplantation cyclophosphamide (OR, 2.23; 95% CI, 1.21 to 4.14; P = .01). Chronic GVHD appeared to be a protective factor (OR, .64; 95% CI, .42 to .96; P = .04). The prognosis of LR is better than in early relapse, with a median OS after LR of 19.9 months. Salvage therapy associated with a second AHSCT improves outcome and is feasible, without creating excess toxicity.

Prognosis of patients with acute lymphoblastic leukaemia relapsing after allogeneic stem cell transplantation

The outcomes of patients with acute lymphoblastic leukaemia (ALL) presenting relapse after allogeneic stem cell transplant (allo-SCT) are poor, with few data available in this setting.

OBJECTIVE AND METHODS

To evaluate the outcomes of patients with ALL presenting relapsed after allo-SCT, we performed a retrospective study including 132 from 11 centres in Spain.

RESULTS

Therapeutic strategies consisted of palliative treatment (n = 22), chemotherapy (n = 82), tyrosine kinase inhibitors (n = 26), immunotherapy with inotuzumab and/or blinatumumab (n = 19), donor lymphocyte infusions (n = 29 pts), second allo-SCT (n = 37) and CAR T therapy (n = 14). The probability of overall survival (OS) at 1 and 5 years after relapse was 44% (95% confidence interval [CI]: 36%; 52%) and 19% (95% CI: 11%; 27%). In the 37 patients undergoing a second allo-SCT, the 5-year estimated OS probability was 40% [22%; 58%]. Younger age, recent allo-SCT, late relapse, 1st complete remission at 1st allo-SCT and chronic graft-versus-host disease confirmed their positive impact on survival in the multivariable analysis.

CONCLUSION

Despite the poor prognosis of patients with ALL presenting relapse after a first allo-SCT, some can be satisfactorily rescued and a second allo-SCT still remains a valid option for selected patients. Moreover, emerging therapies really might improve ALL patients outcome when relapsing after an allo-SCT.

Combining blinatumomab and donor lymphocyte infusion in B-ALL patients relapsing after allogeneic hematopoietic cell transplantation: a study of the SFGM-TC

Relapsed B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic stem cell transplantation (allo-HCT) still represents a major concern with poor outcomes. The aim of this study is to compare the efficacy and safety of blinatumomab and donor lymphocyte infusion (DLI) versus blinatumomab alone in this setting. This is a multicenter retrospective study from centers of SFGM-TC. All transplanted patients who received blinatumomab salvage therapy were included. Patients who received DLI from 1 month before to 100 days after the starting of blinatumomab were included in the blina-DLI group. Seventy-two patients were included. Medium follow-up was 38 months. Fifty received blinatumomab alone and 22 the association blinatumomab-DLI. Two-year overall survival (OS) was 31% in the blinatumomab group and 43% in the blinatumomab-DLI group (p = 0.31). Studying DLI as a time dependent variable, PFS did not significantly differ between the 2 groups (HR:0.7, 95% CI: 0.4-1.5). In multivariate analysis, DLI was not a prognostic factor for OS, progression-free survival and progression/relapse incidence. Adverse events and graft-versus-disease rates were comparable in the 2 groups. In conclusion, adding DLI between 1 month before and 100 days after start of blinatumomab is safe and does not seem to improve outcomes in B-ALL patients who relapsed after allo-HCT.

Second allogeneic hematopoietic stem cell transplantation in patients with acute leukemia relapsed after allogeneic hematopoietic stem cell transplantation

The prognosis of patients with acute leukemia relapsed after allogeneic hematopoietic stem cell transplantation (HSCT) is dismal. We aimed to evaluate the outcomes and prognostic factors of the second HSCT (HSCT2) in acute leukemia patients relapsed after the first HSCT (HSCT1). We analyzed 80 patients who received HSCT2 for relapsed acute leukemia in two Korean institutes. All but four patients received HSCT2 from a donor other than matched sibling donor: an unrelated donor (URD) in 30 and a familial haploidentical donor (FHD) in 46. Forty-four patients (55.0%) were in complete remission (CR) or CR with incomplete count recovery (CRi) at HSCT2, and the median time from HSCT1 to relapse was 9 months. The 2-year overall survival (OS) and event-free survival (EFS) were 21.0% and 17.5%, respectively. The outcomes were similar between URD and FHD. Multivariate analysis demonstrated that disease status (active disease vs. CR/CRi) at HSCT2 and remission duration after HSCT1 were independent prognostic factors for OS and EFS after HSCT2. HSCT2 from URD or FHD was feasible in patients with acute leukemia relapsed after allogeneic HSCT. Also, our study confirmed two critical prognostic factors; disease status at HSCT2 and remission duration after HSCT1.

Outcome predictors after retransplantation in relapsed acute lymphoblastic leukemia: a multicenter, retrospective study

Retransplantation is the only curative treatment option for patients with acute lymphoblastic leukemia (ALL) that has relapsed after allogeneic hematopoietic cell transplantation (allo-HCT); however, data in this setting remain scant. Hence, this multicenter, retrospective study aims to determine outcome predictors after retransplantation in relapsed ALL. We examined 55 recipients who underwent multiple allo-HCTs during 2006-2018. The 2-year overall survival (OS), progression-free survival (PFS), and non-relapse mortality rates were 35.9%, 29.1%, and 23.6%, respectively. We observed a trend of better outcome in Ph + ALL (n = 22) patients compared with non-Ph ALL (n = 33) patients; the 2-year PFS was 40.9% versus 21.2%, indicating a beneficial effect of more potent second- or third-generation tyrosine kinase inhibitors. Univariate analysis revealed that late relapse after the previous transplant was the only significant predictor of better transplant outcome among Ph + ALL patients, whereas factors related to prolonged OS/PFS in non-Ph ALL patients were late relapse after the previous transplant, longer duration from disease relapse/progression to second or more allo-HCT, disease status at the transplantation, and good performance status. Nevertheless, further investigations are warranted to determine whether novel molecular-targeted agents with higher efficacy and fewer toxicities could exceed conventional chemotherapies as a bridging strategy to next allo-HCT and improve the outcomes of non-Ph ALL patients.

Outcome of Relapsed Pediatric Patients After Second Allogeneic Hematopoetic Stem Cell Transplantation: A Retrospective Study From a Single Institution

Prognosis of relapsed leukemia patients after second allogeneic hematopoietic stem cell transplantation (HSCT2) is historically considered very poor. We report the outcome of 18 pediatric patients after failure of HSCT2. The 2-year overall survival was 26% (95% confidence interval [CI], 6-47). The lymphoid malignancies were associated with better survival (40% [95% CI, 12-68]) than myeloid malignancies (0%, P=0.002), together with time to relapse after the HSCT2 (≥5 mo: 44% [95% CI, 12-76] vs. 0% for patients who relapsed within 5 mo from HSCT2, P=0.005), other factors such as sex, donor type, conditioning regimen, and graft versus host disease prophylaxis did not have statistical significance. When the multivariate analysis was carried out, 2 independent protective factors were identified: the lymphoid malignancies and the graft versus host disease 0 to I after HSCT2. When we look at the treatments, patients receiving blinatumomab after relapse got benefit in terms of overall survival and, more importantly, with a long-term control of acute lymphoblastic leukemia.

The consensus on the monitoring, treatment, and prevention of leukemia relapse after allogeneic hematopoietic stem cell transplantation in China

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important curative therapy for patients with leukemia. However, relapse remains the leading cause of death after transplantation. In recent years, substantial progress has been made by Chinese physicians in the field of establishment of novel transplant modality, patient selection, minimal residual disease (MRD) monitoring, and immunological therapies, such as modified donor lymphocyte infusion (DLI) and chimeric antigen receptor T (CART) cells, as well as MRD-directed intervention for relapse. Most of these unique systems are distinct from those in the Western world. In this consensus, we reviewed the efficacy of post-HSCT relapse management practice from available Chinese studies on behalf of the HSCT workgroup of the Chinese Society of Hematology, Chinese Medical Association, and compared these studies withthe consensus or guidelines outside China. We summarized the consensus on routine practices of post-HSCT relapse management in China and focused on the recommendations of MRD monitoring, risk stratification directed strategies, and modified DLI system. This consensus will likely contribute to the standardization of post-HSCT relapse management in China and become an inspiration for further international cooperation to refine global practices.

New approaches in allogenic transplantation in AML

Acute myeloid leukemia (AML) is a heterogeneous disorder with high morbidity and mortality. Allogeneic stem cell transplantation (allo-SCT) is an effective, and sometimes the only, curative postremission therapy for AML patients. Based on genetic risk classification, the published data have suggested that allo-SCT be recommended for high- and most intermediate-risk AML but not for low-risk AML in first complete remission (CR1). Recently, the role of allo-SCT in low-risk AML in CR1 is being established with the development of a risk-directed, minimal residual disease-based strategy. Though human leukocyte antigen-matched sibling transplantation remains the preferred therapeutic option for AML, modern approaches and developments pre-, peri- and post-transplant have facilitated other transplant modalities, especially haploidentical SCT, as promising valid alternative choices. In this paper, we review recent advances in allo-SCT for AML, weigh the benefits of allo-SCT for high-, intermediate-, and even low-risk AML in CR1, discuss the best choice of allo-SCT donor for the treatment of AML, and summarize new approaches for refractory and relapsed AML pre- or post-allo-SCT.